We did the original fuel extension to 88 gallons. When the V8 fell through, we went to the turbo prop. Our wings were closed out so we used heat guns to remove the bottom skins. We installed the kit that Lancair sent us to make the wing virtually all fuel. Just the aileron tube and the aileron bellcrank housing are dry. We also removed the speed brakes. We're told that they are not required on the turbo prop. We installed new bottom skins at a cost of $2600.  We put 59 gallons of Jet A in the left wing and 58.0 in the right wing. The center tank took 13 gallons, giving us a total of about 130 gallons. The center tank fuel is kinda cool because it is forward of the wing fuel thus aiding in the aft CG problem that the turbine is supposed to have. It was a lot of work but we're glad we did it. Regards. Dave.